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ip-num is a zero dependency, TypeScript library for working with IPv4, IPv6 and ASN numbers. It provides representations of these internet protocol numbers with the ability to perform various operations like parsing, validating etc. on them.

ip-num can be used with both TypeScript and vanila JavaScript. It also support both usage within a browser environment as well as Node.Js environment.

ip-num's source can be found on GitHub

You can have a play at ip-num's API via the Runkit at http://bit.ly/ipnum-repl



If you want to use ip-num from within a Node.js environment, you can install it via npm.

npm install ip-num

check the .travis.yml file for the versions of Node.js ip-num is being built and tested with.


If you are using a browser, you would have to use a module bundler like browserify, parceljs, webpack etc. to be able to use ip-num as a front-end module.

For quick prototyping, you can download the release from github at https://github.com/ip-num/ip-num/releases

You can then extract the compressed file and include the ip-num.js file located in the dist folder.


The functionality ip-num exposes can be grouped into 2 broad categories:

  • Modules representing ASN, IPv4, and IPv6 internet protocol numbers
  • Utilities and Validator

How you get access to the above, depends on the module loading mechanism being used. The examples below will show how to access ip-num using ES module mechanism with TypeScript in Node.js, using CommonJs module mechanism with JavaScript in Node.Js, and by including ip-num via a script tag with JavaScript in the browser.

ES module with TypeScript

Import what you need from ip-num and use away

import { Asn } from "ip-num/IPNumber";
import { IPv4 } from "ip-num/IPNumber";
import { IPv6 } from "ip-num/IPNumber";

You can then make use of the imported module in your TypeScript code

let asn = new Asn(65546);
asn.toBinaryString() //10000000000001010

let ipv4 = new IPv4("");
ipv4.toBinaryString() //01001010011111010010101101100011

let ipv6 = new IPv6("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff");
ipv6.toBinaryString() //11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111

CommonJs with JavaScript

All external modules in ip-num are exported and made available via the global ip-num module. So you can require ('ip-num') and then access the module you want to use in your application, or access the module in one go, while requiring; as shown below:

const Asn = require("ip-num").Asn;
const IPv4 = require("ip-num").IPv4;
const IPv6 = require("ip-num").IPv6;

The imported module can then be used:

let asn = new Asn(65546);
asn.toBinaryString() //10000000000001010

let ipv4 = new IPv4("");
ipv4.toBinaryString() //01001010011111010010101101100011

let ipv6 = new IPv6("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff");
ipv6.toBinaryString() //11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111

Via Script tag with JavaScript

Including the ip-num library via the script tag in the browser exposes ipnum variable from which you can access the modules exposes by the library.

<script src="https://ip-num.github.io/ip-num/ip-num.js"></script>
let asn = new ipnum.Asn(65546);
console.log(asn.toBinaryString()); //10000000000001010

let ipv4 = new ipnum.IPv4("")
console.log(ipv4.toBinaryString()); //01001010011111010010101101100011

let ipv6 = new ipnum.IPv6("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff");
console.log(ipv6.toBinaryString()); //11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111


Documentation can be found at https://ip-num.github.io/ip-num/


Find below, some example of the usage of ip-num. For a more comprehensive overview of the API, please refer to the documentation.


An overview covering some part of the module structure of ip-num is represented below:

IPNumber/ -- module that contains IP numbers implementations
├── AbstractIPNum -- contains common implementation to ASN, IPv4 and IPv6 
│   ├── Asn
│   ├── IPv4
|     ├── IPv4Mask
│   ├── IPv6
|     ├── IPv6Mask

IPRange/ -- module that contains IP ranges implementations
├── AbstractIPRange -- contains common implementation for IPv4 and IPv6 CIDR ranges 
│   ├── IPv4CidrRange
│   ├── IPv6CidrRange
├── RangedSet -- Represents a continuous segment of either IPv4 or IPv6 numbers without adhering to classless inter-domain routing scheme

├── Pool -- Represents a collection of IP numbers as single or set


import { Asn } from "ip-num/IPNumber";
// creating
let asA = Asn.fromNumber(1234) // using the fromNumber factory method to create an instance from number
let asB = Asn.fromString("AS1234") // using the fromString factory method to create an instance from string
let asC = Asn.fromString("1234") // string without the "AS" prefix is also supported
let asD = Asn.fromString("1.10") // string in asdot+ format is also supported
let asE = Asn.fromBinaryString('1111') // using the fromBinaryString to create an instance from binary string

// converting between different ASN string representations
Asn.fromNumber(65526).toASDotPlus() // will give "0.65526"
Asn.fromNumber(65546).toASDot() // will give "1.10"
Asn.fromNumber(2).toBinaryString() // will give 10

// check if previous and next values exist, getting previous and next values
Asn.fromNumber(Math.pow(2, 32) - 1).hasNext() // false
Asn.fromNumber(2).hasNext() // true
Asn.fromNumber(0).hasPrevious() // false
Asn.fromNumber(2).hasPrevious() // true

See the ASN documentation for more information


import { IPv4 } from "ip-num/IPNumber";

// creating
let firstIPv4 = new IPv4("") // Creating an instance using the constructor
let secondIPv4 = IPv4.fromNumber(1876843053n) // Using the fromNumber convenience method
let thirdIPv4 = IPv4.fromDecimalDottedString("") // Using the fromDecimalDottedString convenience method
let fourthIPv4 = IPv4.fromBinaryString("01001010011111010010101101100011") // using the fromBinaryString convenience method

// converting an IPv4 instance to binary string representation
firstIPv4.toBinaryString() // will be 01001010011111010010101101100011

// comparing IPV4
firstIPv4.isEquals(thirdIPv4) // false
firstIPv4.isLessThan(thirdIPv4) // true
firstIPv4.isGreaterThan(thirdIPv4) // false

See the IPv4 documentation for more information


import { IPv6 } from "ip-num/IPNumber";

// creating
let firstIPv6 = new IPv6("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff") // Creating an instance using the constructor
let secondIPv6 = IPv6.fromNumber(100) // Using the fromNumber convenience method
let thirdIPv6 = IPv6.fromHexadecimalString("::") // Using the fromDecimalDottedString convenience method. Not abbreviated representation of IPv6 string is supported
let fourthIPv6 = IPv6.fromBinaryString("01001010011111010010101101100011") // using the fromBinaryString convenience method
// converting an IPv6 instance to binary string representation
firstIPv6.toBinaryString() // will be 11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
// comparing IPV6
firstIPv6.isEquals(thirdIPv6) // false
firstIPv6.isLessThan(thirdIPv6) // false
firstIPv6.isGreaterThan(thirdIPv6) // true

See the IPv6 documentation for more information

IPv4 Ranges

import {IPv4CidrRange} from "ip-num/IPRange";

// creating an IPv4 range from CIDR notation
let ipv4Range = IPv4CidrRange.fromCidr("");

// get first and last IPv4 number in the range
ipv4Range.getFirst().toString() // gives
ipv4Range.getLast().toString() // gives

// getting number of IPv4 numbers in the range
ipv4Range.getSize() // Returns 256

// splitting ranges
ipv4Range.split()[0].toCidrString() // returns
ipv4Range.split()[1].toCidrString() // returns

Performing set like operations with IP Ranges:

import {IPv4CidrRange} from "ip-num/IPRange";

let containerRange = IPv4CidrRange.fromCidr("");
let firstRange = IPv4CidrRange.fromCidr("");
let secondRange = IPv4CidrRange.fromCidr("");

console.log(containerRange.inside(firstRange)) // false

console.log(containerRange.inside(secondRange)) // false;

console.log(firstRange.inside(containerRange)); // true;
console.log(secondRange.inside(containerRange)); // true;

See the IPv4CidrRange documentation for more information

IPv6 Ranges

import {IPv6CidrRange} from "ip-num/IPRange";

// creating an IPv6 range from CIDR notation
let ipv6Range = IPv6CidrRange.fromCidr("2001:db8::/33");

// get first and last IPv6 number in the range
ipv6Range.getFirst().toString() // gives 2001:db8:0:0:0:0:0:0
ipv6Range.getLast().toString() // gives 2001:db8:7fff:ffff:ffff:ffff:ffff:ffff

// getting number of IPv6 numbers in the range
ipv6Range.getSize() // Returns 39614081257132168796771975168

// splitting ranges
ipv6Range.split()[0].toCidrString() // returns 2001:db8:0:0:0:0:0:0/34
ipv6Range.split()[1].toCidrString() // returns 2001:db8:4000:0:0:0:0:0/34

Performing set like operations with IP Ranges:

import {IPv6CidrRange} from "ip-num/IPRange";
let containerRange = new IPv6CidrRange(new IPv6("2001:db8::"), new IPv6Prefix(47));
let firstRange = new IPv6CidrRange(new IPv6("2001:db8::"), new IPv6Prefix(48));
let secondRange = new IPv6CidrRange(new IPv6("2001:db8:1::"), new IPv6Prefix(48));

console.log(containerRange.inside(firstRange)); // false
console.log(containerRange.inside(secondRange)); // false;

console.log(firstRange.inside(containerRange)) // true;
console.log(secondRange.inside(containerRange)) // true;

See the IPv6CidrRange documentation for more information

AbstractIPNum and AbstractIPRange

When working in TypeScript, you have the ability to abstract ASN, IPv4 and IPv6 as an AbstractIPNum, and IPv4CidrRange and IPv6CidrRange as AbstractIPRange

import {AbstractIPNum} from "ip-num/IPNumber";
import {AbstractIPRange} from "ip-num/IPRange";
import {Asn} from "ip-num/IPNumber";
import {IPv4} from "ip-num/IPNumber";
import {IPv6} from "ip-num/IPNumber";
import {IPv4CidrRange} from "ip-num/IPRange";
import {IPv6CidrRange} from "ip-num/IPRange";
import {IPv4Prefix} from "ip-num/Prefix";
import {IPv6Prefix} from "ip-num/Prefix";

// representing ASN, IPv4 and IPv6 as a AbstractIPNum
let ipNumbers: AbstractIPNum[] = [];
ipNumbers.push(new Asn("200"));
ipNumbers.push(new IPv4(""));
ipNumbers.push(new IPv6("2001:800:0:0:0:0:0:2002"))

// console logs AS200
//              2001:800:0:0:0:0:0:2002
ipNumbers.forEach(ip => {

// representing IPv4CidrRange and IPv6CidrRange as AbstractIPRange

let ipRanges: AbstractIPRange<IPv4 | IPv6, IPv4Prefix | IPv6Prefix>[] = [];

// console logs
//               2001:db8:0:0:0:0:0:0/33
ipRanges.forEach(iprange => {

See the IPNumber documentation for more information See the IPRange documentation for more information

IPv4Mask and IPv6Mask

IPv4Mask and IPv6Mask are used to represent subnet masks in IPv4 and IPv6 respectively.

Subnet masks are in all respects IP numbers with the only restriction that they must contain contiguous on bits (1's) followed by contiguous off bits (0's). This means IPv4Mask and IPv6Mask can perform all the operations available on IPv4 and IPv6. The only difference is that the invariant required for a subnet is enforced in the constructor of IPv4Mask and IPv6Mask. For example:

The following code will throw an exception:

import {IPv4Mask} from 'ip-num/IPNumber'
import {IPv6Mask} from 'ip-num/IPNumber'

let ipv4Mask = new IPv4Mask("");
let ipv6Mask = new IPv6Mask("3ffe:1900:4545:0003:0200:f8ff:fe21:67cf");

While the following code works fine:

import {IPv4Mask} from 'ip-num/IPNumber'
import {IPv6Mask} from 'ip-num/IPNumber'

let iPv4Mask = new IPv4Mask("");
let iPv6Mask = new IPv6Mask("ffff:ffff:ffff:ffff:ffff:ffff:0:0");

See the IPv4Mask documentation for more information See the IPv6Mask documentation for more information

IPv4-Mapped IPv6 Address Support

IPv4-Mapped IPv6 Address IPv6 allows embedding an IPv4 address within an IPv6 address. See IPv6 Addresses with Embedded IPv4 Addresses

ip-num offers various ways to create an IPv4-Mapped IPv6 Address:

Converting from an existing IPv4
import { IPv4 } from "ip-num/IPNumber";

let ipv4 = new IPv4("")
ipv4.toIPv4MappedIPv6().toString() // produces ::ffff:4a7d:2b63
From an existing IPv4 using convenience method on IPv6
import { IPv6 } from "ip-num/IPNumber";
import { IPv4 } from "ip-num/IPNumber";

let ipv6 = IPv6.fromIPv4(new IPv4(""))
ipv6.toString() // produces ::ffff:4a7d:2b63
From dot-decimal notation using convenience method on IPv6
import { IPv6 } from "ip-num/IPNumber";

let ipv6 = IPv6.fromIPv4DotDecimalString("")
ipv6.toString() // produces ::ffff:4a7d:2b63

IP Pool

Pool allows for working with collections of IP numbers and ranges.

Creating Pools from list of IP numbers and converting to IP ranges

import {IPv4} from "ip-num/IPNumber";
import {Pool} from "ip-num/IPPool";

let pool = Pool.fromIPNumbers([

let ranges = pool.getRanges();
console.log(ranges[0].toCidrRange().toCidrString()); // prints ""
console.log(ranges[1].toCidrRange().toCidrString()); // prints ""

Aggregating IP ranges

import {IPv4} from "ip-num/IPNumber";
import {Pool} from "ip-num/IPPool";
import {RangedSet} from "ip-num/IPRange";
import {IPv4CidrRange} from "ip-num/IPRange";

let arrays: RangedSet<IPv4>[] = new Array<RangedSet<IPv4>>();


let pool = Pool.fromRangeSet(arrays);
let aggregatedPool = pool.aggregate();

console.log(aggregatedPool.getRanges()[0].toRangeString()) // prints("");
console.log(aggregatedPool.getRanges().length) // prints 1;

Validation and Utilities

Various validation are exposed via the Validator module. ip-num also provide various utility operations. These utility operations can be found in BinaryUtils, IPv6Utils, and HexadecimalUtils.

For example to expand and collapse IPv6 numbers:

import * as IPv6Utils from 'ip-num/IPv6Utils'

// expanding
IPv6Utils.expandIPv6Number("::") // Expands to 0000:0000:0000:0000:0000:0000:0000:0000
IPv6Utils.expandIPv6Number("FF01::101")// Expands to FF01:0000:0000:0000:0000:0000:0000:0101
// collapsing
IPv6Utils.collapseIPv6Number("0000:0000:0000:0000:0000:0000:0000:0000") // Collapses to :: 
IPv6Utils.collapseIPv6Number("FF01:0:0:0:0:0:0:101") // Collapses to FF01::101

To check if a given string is valid cidr notation:

import {Validator} from 'ip-num/Validator'

let result = Validator.isValidIPv4CidrNotation("123.234.334.23")
// result => [false, ["Cidr notation should be in the form [ip number]/[range]"]]
let result = Validator.isValidIPv4CidrNotation("")
// result => [true, []]

See the Validator documentation for more information See the BinaryUtils documentation for more information See the IPv6Utils documentation for more information See the HexadecimalUtils documentation for more information


The ip-num library is released under the MIT license


To discuss a new feature or ask a question, open an issue. Find the issue tracker here

Found a bug and you want to provide a fix for it? Then feel free to submit a pull request. It will be appreciated if the changes made are backed with tests.

Change log

View latest releases here

  • Introduced AbstractIpRange to abstract over the IPRange (ie: IPv4Range and IPv6Range). Issue #15
  • Extend the IPRange interface. Issue #20
  • Add method to IPRange to return the adjacent ranges. Issue #19
  • Add ability to validate if a CIDR notation represents a valid range. Issue #21
  • Changed target to es5 so as to support Internet Explorer 11. Issue #22
  • Fixed isValidIPv4String() incorrectly returns true for some invalid addresses. Issue #9
  • Improved Validator.isValidIPv6String and added test coverage. Issue #10
  • Added convenient methods for creating IPv4 (IPv4.fromBinaryString) and IPv6 (IPv6.fromBinaryString) from binary string Issue #11
  • Added convenient methods for creating ASN (ASN.fromBinaryString) Issue #13
  • Prepend with "::" if toString value for IPv6 has leading zeros. Issue #12
  • Implemented support for IPv4-Mapped IPv6 Address. Issue #3

Version 1.1.0 was Unpublished.

  • Renamed Subnet to SubnetMask Issue #1
  • Fixed the throwing of invalid integer: NaN when invalid IPv4 and IPv6 strings are passed to Validator .isValidIPv4String and Validator.isValidIPv6String validators. Fixed by saiyeek Issue #5
  • Fixed Validator.isValidIPv4CidrNotation improper validation of IPv4 CIDR Issue #6


Special thanks to JetBrains for supporting the development of ip-num with a free IDE licence.

You can find more information about JetBrains support for open source projects here


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